Acidic galvanic copper bath

ABSTRACT

An acidic galvanic copper bath of customary composition with organic sulfonic acids or the salts thereof as basic luster substances and/or with anion active and/or non-ionogenic wetting agents, in which the bath includes substituted urea derivatives.

United States Patent Immel 1 Dec. 2, 1975 1 1 AClDlC GALVANIC COPPER BATH [75] Inventor: Waldemar lmmel, Solingen, [561 References Cited Germany UNITED STATES PATENTS 73 Assigneez w Kampschulte & Cie. solingen 2,828,252 3/1958 Fischer .i 204/52 R X Germany 2,910,413 10/1959 Strauss ct a1.....

3,414,493 12/1968 Nobel ct a1. 204/52 R [22] Filed: Sept. 27, 1974 3,704,213 11/1972 Fournier 204/52 R [21] Appl' 510325 Primary ExaminerG. L. Kaplan Related US. Application Data Attorney, Agent, or Firm-walter Becker [63] Continuation of Ser. No. 334,296, Feb. 21, 1973,

abandoned. [57] ABSTRACT An acidic galvanic copper bath of customary composi- [301 Forelgn Apphcatlon Pnomy Data tion with organic sulfonic acids or the salts thereof as F613. 22, 1972 Germany 2208198 basic luster ubstances and/gr anion active and/Or non-ionogenic wetting agents, in which the bath in- U-S. R eludes substituted urea derivatives [51] Int. Cl. C25D 3/38 [58] Field of Search 204/52 R, 44, I06 3 Drawmgs ACIDIC GALVANIC COPPER BATH This application is a continuation of U.S. application Ser. No. 334,296 filed on Feb. 21, 1973, which is now 2 and which is built into the molecule of the sulfonic acids or the salts thereof. Preferably, the copper bath according to the present invention is characterizedb-y an additional content in Nlmono andlor di/urea substiabandoned. 5 tuted with alkylmercapto groups. Expedi''ntlyIthe cop- The present invention relates to an acidic galvanic per bath contains the substances which are employed high luster copper bath of the customary composition as flattening and lustering agents in conformitywith the with a content in organic sulfonic acids or the salts present invention in quantities of from-5.10" to 2.l0 thereof as basic lustering agent and/or a content in ang/l, preferably from 3.10 to 75.10 g/l. As examples ionactive and/or nonionogenic wetting agents. for such compounds according to the invention there Acidic high luster copper baths permit the separation may be mentioned:

cu -cu cit-cu, 1 1. H,C N--|('I-S-CH,HNfiNH-CH,Sfi- -N CH,

\ cH, cH, s o s Cl-l,CH,

2. l-hC-Cl-h-CH, CH,CH2CH,

l N-(i-S-CH,-HNC--NH-CH S-$N a l l l H,C-CH,--CH s s CH,-CH,-CH,

3. int: C l-l,

N c-s cii,-i m e NH-cri,-s ci N H5C/ S l L z u 4. Cli -CH, CH,--CH,

O N-fi--SCH,-HNC--NH-CH,-Sfi-N\' O CH,CH, S S CH,--CH,/;

or precipitation of high luster copper deposits which with various types of baths are also well flattened. The acidic copper deposits are ductile, free from pores and yield a very good corrosion protection. A particular advantage of the acidic high luster copper baths is seen in their great economy, low working temperatures and the simple detoxication or decontamination with regard to the removal of cyanogen. The addition of the luster and flattening substances is generally effected in conformity with the measured or calculated Ampere hours.

It is known in acidic galvanic copper baths of customary composition with a content in organic sulfonic acids for purposes of obtaining a flattening effect to employ such derivatives of thiourea which in the molecular bond in addition to the thiourea component also comprise one or more groups in which the carbon atom is bonded exclusively to heteroatoms, such as sulfur and nitrogen. These organic sulfonic acids impart upon the baths intermixed therewith flattening properties, but as chemical compounds on the thiourea basis they have the drawback that, when the acidic copper electrolyte is left standing without current passing therethrough, the sulfonic acids will in view of their thiourea/Isothiourea tautomerism with regard to their reactive SH-grouping be strongly subjected to selfdisintegration. As a further drawback it has been found that such baths have only a low concentration-dependent tolerance as to action.

It is, therefore, an object of the present invention to overcome the above mentioned drawbacks of the heretofore known acidic galvanic copper baths without affecting the deposit of the high luster and well flattened copper precipitation.

This object has been realized according to the present invention by the fact that the bath instead of containing the thiourea component contains the urea component which tends considerably less to tautornerism EXAMPLE 200 g/l 55 g/l SOmg/l mg/l copper sulfate sulfuric acid chlorine ions N,N-diprophyldithiocarbamine acid propylester w-sodium combined with a sulfo acid 6 mg/l (hexamethylendithiocarbamylmethylene)-urea 1 g/l non-ionogenic wetting agent working temperature 20 30C current density 0.75 5.5 Arnp/dm When copper plating prenickel plated steel sheet metal with a starting rough depth of 0.6 p. m, with a current density of from 5 Amp/dm there is obtained a lustrous copper layer or coating with a flattening of approximately 60%. The bath may be operated with and without air.

It is, of course, to be understood that the present invention is, by no means, limited to the specific example set forth above but also comprises any modifications within the scope of the appended claims.

What I claim is: 1. in an acidic galvanic copper bath the improvement comprising providing the bath with a substituted urea selected from the group consisting of 3. HC\ e s NCS-CH -HNCNH-CH,S U N and H;C2 C2:

4. Cl-l -CH, CHz-CH O Nfi-SCH;HNENH-CH,-Sfi-N\ O CHI-CH2 S S Cl-h-CH 2. A copper bath of claim 1 wherein the substituted 3. A copper bath of claim 1 wherein the substituted urea is present in an amount from 5 X 10* to 2 grams urea is present in an amount from 3 X 10" to 7.5 X per liter. 10 grams per liter. 

1. IN AN ACIDIC GALVANIC COPPER BATH THE IMPROVEMENT COMPRISING PROVIDING THE BATH WITH A SUBSTITUTED UREA SELECTED FROM THE GROUP CONSISTING OF (PIPERIDINO-C(=S)-S-CH2-NH-)2-C=O
 2. A copper bath of claim 1 wherein the substituted urea is present in an amount from 5 X 10 4 to 2 grams per liter.
 3. A copper bath of claim 1 wherein the substituted urea is present in an amount from 3 X 10 3 to 7.5 X 10 2 grams per liter. 